This invention relates to an industrial robot, and more particularly to an industrial robot capable of operating effectively even in a very limited amount of floor space.
Industrial robots are often employed in machine tool operations and are adapted to exchange tools and workpieces so that the machining operation can proceed in a fully automatic manner. Industrial robots employed in such automated operation must meet a number of important requirements: they should permit a task to be performed quickly; they should be installable even where space is limited; and they should process freedom of movement along a straight line as required to mount and dismount a workpiece.
Hitherto disclosed industrial robots used for automatic machine tool operation have been designed on the basis of cylindrical and polar coordinate systems or the like. In these industrial robots an elongated, rodlike arm having a manipulator attached at one end is rotated about a fixed position which serves as the center of rotation, and the arm is extended or retracted to vary the distance between the manipulator and the center of rotation. Such an arrangement results in a large distance between the handling portion of a workpiece mounted in a machine tool, such as the position of a chuck in a lathe, and the center of rotation of the robot. In addition, the arm projects rearwardly of the center of rotation to a great extent. For these reasons the installed robot must be provided with a large surrounding floor space so that the robot will not interfere with adjacent equipment when going through its various motions. Much of this space is dead space. Moreover, since the arm is merely a single rod or shaft, a wide variety of manipulative operations is obviously impossible, and freedom of movement along a straight line for mounting and dismounting the workpiece is lost. Thus it has not been possible to fully meet the requirements of an industrial robot as set forth above.